Everything you need to know about GHK Cu WHAT IS IT? A copper peptide your body naturally produces but production drops by 60% by age 60. It's one of the most GHK Cu is a small copper bound peptide (glycyl histidyl lysine with a copper ion) found naturally in human tissues and fluids. Its levels decline with age, and it plays a role in tissue repair, regeneration, Dosing Guide for GHK Cu 100mg GHK Cu Peptide The benefits, side effects, and more [2026]